A mechanical device, such as a power tool, includes a housing, a motor supported by the housing and connectable to a power source to operate the motor, the motor including a motor shaft, a gear case connected to the housing and a drive mechanism supported by the gear case and driven by the motor. A flange separates the gear case and the housing and defines an opening which communicates between the housing and the gear case. The motor shaft extends through the opening and drivingly engages the drive mechanism. Grease is provided in the gear case to lubricate the engagement area of the motor shaft and the drive mechanism and to lubricate the components of the drive mechanism.